Various types of valved containers are well known. Such containers are commonly used to contain toxic, unstable, reactive, unknown or other potentially hazardous materials. For simplicity, these materials will be generally referred to as hazardous materials.
Valved containers are generally accessed by actuation of the valve or valves integrally associated with the container. Valve actuation generally involves rotation of a valve from a closed position to an open position. Valve actuation provides access to the contents of the valved container, for example, by venting the material from the container. Manual actuation of valves containers can be dangerous or otherwise undesired under certain circumstances. This is especially so with containers housing hazardous materials.
Remote valve actuation techniques are generally known and have been used in some applications. Remote valve actuators have been used in some situations to open valves which are normally manually opened. Remote valve actuation is typically preferred where safety and environmental concerns associated with the valved container contents exist, especially where such contents may be toxic, unstable, reactive or otherwise potentially dangerous. Remotely actuated valves have been used in conjunction with "gas cabinets" which are boxes vented to an appropriate treatment system.
In some instances, attempted manual valve actuation may result in leakage, uncontrolled reactions, or other problems. In such circumstances, the use of remote valve actuation may provide some isolation of personnel, but typically does not offer containment of the contents. Content containment is particularly desirable where the container contents are unknown or hazardous.
In some cases, neither remote nor manual valve actuation is suitable. For example, valve actuation may not be effective for accessing container contents where the valve is defective or where the valve body is blocked (eg., by corrosion products or polymerized materials). For such situations it may be necessary to access the contents through alternative mechanisms. One such alternative is using what is referred to as a Cylinder Rupture Vessel ("CRV"). For example, CRVs such as those described in U.S. Pat. No. Re. 33,799 entitled "Cylinder Rupture Vessel"; 4,944,333 entitled "Cylinder Rupture Vessel with Clamps for Immobilizing a Container Within the Vessel;" U.S. Pat. No. 5,186,219 entitled "Cylinder Rupture Vessel;" U.S. Pat. No. 5,339,876 entitled "Apparatus and Methods for Removing Hazardous Contents from Compressed Gas Cylinders;" U.S. Pat. No. 5,383,498 entitled "Cylinder Rupture Vessel with Cylinder Rotation Mechanism and Rupture Mechanism;" U.S. Pat. No. 5,383,499 entitled "System for Removal of Unknown, Corrosive, or Potentially Hazardous Gases From a Gas Container;" U.S. Pat. No. 5,427,157 entitled "Apparatus and Method for Controlled Penetration of Compressed Fluid Cylinders;" U.S. Pat. No. 5,474,114 entitled "Apparatus and Method for Controlled Penetration of Compressed Fluid Cylinders;" U.S. Pat. No. 5,499,665 entitled "Cylinder Rupture Vessel;" U.S. Pat. No. 5,584,325 entitled "Apparatus and Method for Controlled Penetration of Compressed Fluid Cylinders;" and U.S. Pat. No. 5,613,533 entitled "Cylinder Rupture Vessel;" enable access to the contents of containers (including, but not limited to cylinders with inoperable valves) in a controlled environment. Such containers may be cylinders, munitions, drums or other containers, containing either known or unknown substances. For simplicity, the term "container" will be used herein broadly to refer to cylinders, munitions, drums or other containers containing known or unknown substances (whether pressurized or not).
The general structure and operation of a sealable recovery vessel, such as a CRV, is described, for example, in the aforementioned patents which are incorporated herein by reference in their entirety. Briefly, a CRV generally comprises a sealed chamber with an access door for enabling a container to be located therein on a support surface. A sealing mechanism is provided to seal the chamber. Inlet and outlet ports may be provided for creating a vacuum and/or introducing inert gas into the CRV and for purging air and inert gas from the container to control the environment during processing of the container. In a CRV, an access mechanism is typically provided for gaining access to the inside of the container. Access can be obtained, for example, by rupturing a wall of the container using a rupture mechanism such as a punch, spike, drill, projectile or saw or by shearing the container near the valve to remove the valve. The term "rupture" is understood broadly to mean gaining access to the interior of the container by penetrating a wall or a portion of the container by these or other mechanisms. In some prior CRVs, the container is held stationary by chains or other securing mechanisms. It is also known to invert the container after rupturing to facilitate the removal of its contents, especially when those contents are liquids. Other functions and feature of CRVs are disclosed in the aforementioned patents.
Accessing the contents of a container by use of a CRV enables controlled access to the contents of the container. For example, the CRV may prevent leakage of the contents into the environment and may be designed to withstand explosions caused by accessing the contents should they occur in the CRV. The use of a CRV provides these and other safety advantages, especially where normal valve operation is not possible. However, the use of a CRV can be more costly than normal valve operation. Remote valve actuation outside of a CRV can be cheaper, but presents certain risks. Thus, existing systems leave the alternatives of deciding whether to use a cheaper, potentially unsafe approach to access a valved container or to use a safer but potentially more costly approach.
Other techniques have been developed in an attempt to deal with accessing valved cylinders. For example, a device for removing a cylinder valve inside of an "overpack" by unscrewing the valve from the cylinder body is known. This device does not permit actuation of the valve. Rather, it removes the valve. This technique has various drawbacks and safety issues. For example, some potential drawbacks are that the valve body may be corroded to the cylinder and thus not removable, the valve may break without releasing the contents, and removal of the valve may leave corrosion product remaining in the cylinder, which may block the valve orifice. Other drawbacks also exist.
It is known that liquid filled containers may be fitted with dip tubes attached to the valve mechanism to remove liquid contents. One drawback of this technique is that these tubes do not permit all of the product to be removed and, typically, a significant quantity is left in the container which cannot be removed in a liquid phase through the valve. The residual content may be particularly significant in the case of large containers such as ton containers. This is a drawback with existing dip tubes.
These and other drawbacks exist in heretofore known systems.